Radio-frequency identification (RFID) tags contain electronically stored information. The RFID technology has been used for years for the purposes of automatically identifying and tracking tags attached to objects, and hence to track the objects themselves (e.g. inventory, stock). Some RFID tags are powered by and read at short distances, for example a few meters, via electromagnetic induction, and act as a passive transponder. Other RFID tags may utilize a local power source, for example a battery, and may transmit radio signals comprising stored information. An RFID reading device can be either passive or active.